Expandable member for deploying a prosthetic device

ABSTRACT

An apparatus for delivering a prosthetic device through the vasculature of a patient includes a radially expandable member coupled to the distal end of an elongate shaft. The expandable member has an open frame configuration and an outer mounting surface for mounting the prosthetic device in a collapsed state thereon. The expandable member expands radially outwards from a first configuration to a second configuration to expand a prosthetic device mounted thereon.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/880,616, filed Oct. 12, 2015, which is a continuation of U.S. patentapplication Ser. No. 14/338,001, filed Jul. 22, 2014, now U.S. Pat. No.9,161,834, which is a continuation of U.S. patent application Ser. No.13/910,348, filed Jun. 5, 2013, now U.S. Pat. No. 8,784,480, which is acontinuation of U.S. patent application Ser. No. 12/396,378, filed Mar.2, 2009, now U.S. Pat. No. 8,460,368, which claims the benefit of U.S.Provisional Application No. 61/032,851, filed Feb. 29, 2008, all whichare hereby incorporated by reference.

FIELD

The present invention relates generally to medical devices and methods.More particularly, the present invention provides minimally invasivemethods and devices for percutaneous transcatheter implantation ofexpansible prosthetic heart valves within or adjacent a valved anatomicsite within the heart.

BACKGROUND

When treating certain medical conditions, it is sometimes desirable toexpand a frame or other radially expandable member in an orifice orconduit of a patient's body. For example, expandable tubes called stentsare commonly inserted into a natural conduit of a patient's body andexpanded inside the conduit to hold the conduit in an open position.Such expandable stents can be used to expand, widen, or otherwiseprovide structural support to various conduits of the human body,including, for example, arteries, veins, bile ducts, the esophagus, andthe colon. In other treatment procedures, prosthetic heart valves thatinclude a frame member are implanted into the body at a treatment site(e.g., a heart valve annulus). These prosthetic heart valves can bepositioned in the heart valve annulus by expanding the frame member toroughly the size of the valve annulus.

Such frames or stents can be self-expanding or expanded using anexpansion balloon. One conventional method involves positioning a frameon a balloon of a balloon catheter, maneuvering the balloon and frame tothe treatment site, and inflating the balloon with a fluid to expand theframe or stent to the desired size. Such an approach, however, can havedrawbacks. For example, during the expansion of the balloon the orificeor conduit is usually at least partially, if not completely, occluded,which can cause certain undesirable effects. Accordingly, it isdesirable to provide methods and delivery systems that eliminate orreduce these and other potential drawbacks.

SUMMARY

In the deployment of prosthetic devices in the aortic arch or in theintracranial arteries, blockage of the lumen by the balloon during theimplantation process, even for a short period of time, can introducecomplications to the medical procedure. The apparatuses and methodsdescribed in various embodiments herein can reduce and/or substantiallyeliminate the occlusion of the lumen (e.g., artery or other passageway)during expansion of a prosthetic device therein.

The apparatuses and methods described in various embodiments herein canprolong prosthetic device deployment time, eliminate pacing and itsassociated risks, as well as permitting repositioning of the prostheticdevice during deployment.

In one embodiment, an apparatus for delivering a prosthetic devicethrough the vasculature of a patient comprises an elongate shaft havinga distal end and a radially expandable member coupled to the distal endof the elongate shaft. The expandable member can comprise a distal endportion and a proximal end portion that are movable relative to oneanother between a first orientation and a second orientation. Aplurality of struts can be coupled to at least one of the distal end andproximal end portions of the expandable member and can have a prostheticdevice receiving area. In the first orientation the distal end andproximal end portions are a first distance apart, and in the secondconfiguration the distal end and proximal end portions are a seconddistance apart. The second distance can be less than the first distance.Movement of the distal end and proximal end portions from the firstorientation to the second orientation can cause connecting members toexpand radially outwards from a first configuration to a secondconfiguration to expand the prosthetic device

In specific implementations, the expandable member can comprise a screwmember that extends between the distal end portion and the proximal endportion, and rotation of the screw member can cause the distal end andproximal end portions to move from the first to the second orientation.In other specific implementations, the expandable member can comprise awire that extends between the distal end portion and the proximal endportion, and movement of the wire can cause the distal end and proximalend portions to move from the first to the second orientation.

In other specific implementations, one or more of the plurality ofstruts can extend from the distal end portion to the proximal endportion. In other specific implementations, the expandable member cancomprise a cover that at least partially surrounds the plurality ofstruts. In other specific implementations, the cover can be configuredto open to permit fluid to flow through the expandable member from thedistal end portion to the proximal end portion and to close tosubstantially prevent fluid from flowing through the expandable memberfrom the proximal end portion to the distal end portion. In otherspecific implementations, the cover can have at least one slit near theproximal end portion to allow the cover to open.

In specific implementations, one or more of the plurality of struts canbe configured to expand in a predetermined manner. In other specificimplementations, one or more of the plurality of struts can have a notchat an internal face of a desired bending point to facilitate expansionof the expandable member in the predetermined manner.

In other specific implementations, some of the plurality of struts canextend from the distal end portion and some of the plurality of strutscan extend from the proximal end portion. The prosthetic device can beremovably coupled at a first end to the struts that extend from thedistal end portion and at a second end to the struts that extend fromthe proximal end portion.

In another embodiment, an apparatus for delivering a prosthetic devicethrough the vasculature of a patient comprises an elongate shaft havinga distal end and a radially expandable member coupled to the distal endof the elongate shaft. The expandable member can have an open frameconfiguration and an outer mounting surface for mounting the prostheticdevice in a collapsed state thereon. The expandable member can beconfigured to expand radially outwards from a first configuration to asecond configuration to expand the prosthetic device.

In specific implementations, the expandable member can comprise a screwmember that extends between the distal end portion and the proximal endportion, and rotation of the screw member can cause the distal end andproximal end portions to move closer together and cause the plurality ofstruts to expand radially.

In other specific implementations, the expandable member can comprise aplurality of longitudinally extending struts that extend between adistal end portion and a proximal end portion. In other specificimplementations, one or more of the plurality of struts are configuredto expand in a predetermined manner.

In other specific implementations, the expandable member can comprise acover that at least partially surrounds the plurality of struts. Thecover can be configured to open to permit fluid to flow through theexpandable member from the distal end portion to the proximal endportion and to close to substantially prevent fluid from flowing throughthe expandable member from the proximal end portion to the distal endportion. In specific implementations, the cover has at least one slitnear the proximal end portion to allow the cover to open.

In another embodiment, a method for delivering a prosthetic devicethrough the vasculature of a patient is provided. The method cancomprise providing an expandable member at a distal end of an elongateshaft, coupling the prosthetic device to the plurality of struts, andexpanding the expansion device from a first configuration to a secondconfiguration to expand the prosthetic device. The expandable member canhave plurality of struts that form an open frame configuration.

In other specific implementations, the expandable member can comprise aplurality of struts that extend from a distal end portion of theexpandable member to a proximal end portion of the expandable member andthe method can further comprise the act of reducing the distance betweenthe distal end portion and the proximal end portion to cause theplurality of struts to radially expand.

In other specific implementations, at least some of the plurality ofstruts can extend from a distal end portion of the expandable member andat least some of the plurality of struts extend from a proximal endportion of the expandable member, and the prosthetic device can bereleaseably coupled at a first end to the struts that extend from thedistal end portion and at a second end to the struts that extend fromthe proximal end portion. The method can further comprise releasing theprosthetic device from the plurality of struts. In other specificimplementations, after expanding the prosthetic device, the expandablemember can be collapsed back to the first configuration and retractedfrom the body.

The foregoing and other advantages of the various embodiments disclosedherein will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an expandable member for implanting aprosthetic device within the body.

FIG. 2 is a side view of the expandable member of FIG. 1.

FIG. 3 is an end view of the expandable member of FIG. 1.

FIG. 4 is a side view of a portion of an expandable member.

FIG. 5 is a view of an expandable member, shown in a collapsedconfiguration and with portions removed for clarity.

FIG. 6 is a view of an expandable member, shown in a partially collapsedconfiguration and with portions removed for clarity.

FIG. 7 is a view of an expandable member, shown in an expandedconfiguration and with portions removed for clarity.

FIG. 8 is a cross-sectional view of a delivery system with an expandablemember.

FIG. 9 is a partial cross-sectional view of a delivery system with anexpandable member and a prosthetic device mounted thereon.

FIG. 10 is a view of a delivery system with an expandable member and aprosthetic device mounted thereon, shown with a cover and with theexpandable member in an expanded configuration.

FIG. 11 is a partial cross-sectional view of an expandable member with acover at least partially surrounding the expandable member.

FIG. 12 is a view of an expandable member with a cover at leastpartially surrounding the expandable member, with the cover shown in anopen configuration.

FIG. 13 is a partial cross-sectional view of a prosthetic device beingexpanded within the body by an expandable member.

FIG. 14 is a view of a delivery system with an expandable member, shownwith a prosthetic device mounted thereon.

FIG. 15 is a view of a delivery system with an expandable member andprosthetic device mounted there, shown in an expanded configuration.

FIG. 16 is a view of a delivery system with an expandable member at atreatment site in the body, with a prosthetic device shown in anexpanded configuration.

FIG. 17A is a delivery system with an expandable member and a collapsedprosthetic device mounted thereon.

FIG. 17B is a cross-sectional view taken at line 17B-17B of FIG. 17A.

FIG. 18 is a view of a strut of an expandable members and a connectionmeans for connecting the strut to a prosthetic device.

FIG. 19 shows a view of an anchoring device.

FIG. 20 shows a view of the anchoring device of FIG. 19 positionedwithin the body to hold a prosthetic device in position relative to theanchoring device.

FIG. 21A shows a cross-sectional view of a delivery system with theanchoring device shown in FIG. 19, with the anchoring device shown in anon-deployed state.

FIG. 21B shows a cross-sectional view of a delivery system with theanchoring device shown in FIG. 19, with the anchoring device shown in adeployed state.

FIG. 22 shows an illustration of a delivery system that has anexpandable member that is deployable by a ratchet mechanism.

FIG. 23 shows an illustration of a shaft suitable for use with thedelivery system of FIG. 22.

FIG. 24 shows an illustration of a mechanism for use with a deliverysystem of the type shown in FIG. 22.

FIG. 25 shows an illustration of a delivery system with an expandablemember that is operable using an actuation device positioned adjacentthe expandable member.

DETAILED DESCRIPTION

The following description is exemplary in nature and is not intended tolimit the scope, applicability, or configuration of the invention in anyway. Various changes to the described embodiment may be made in thefunction and arrangement of the elements described herein withoutdeparting from the scope of the invention.

As used in this application and in the claims, the singular forms “a,”“an,” and “the” include the plural forms unless the context clearlydictates otherwise. Additionally, the term “includes” means “comprises.”Further, the terms “coupled” and “associated” generally meanselectrically, electromagnetically, and/or physically (e.g., mechanicallyor chemically) coupled or linked and does not exclude the presence ofintermediate elements between the coupled or associated items.

Although the operations of exemplary embodiments of the disclosed methodmay be described in a particular, sequential order for convenientpresentation, it should be understood that disclosed embodiments canencompass an order of operations other than the particular, sequentialorder disclosed. For example, operations described sequentially may insome cases be rearranged or performed concurrently. Further,descriptions and disclosures provided in association with one particularembodiment are not limited to that embodiment, and may be applied to anyembodiment disclosed.

Moreover, for the sake of simplicity, the attached figures may not showthe various ways (readily discernable, based on this disclosure, by oneof ordinary skill in the art) in which the disclosed system, method, andapparatus can be used in combination with other systems, methods, andapparatuses. Additionally, the description sometimes uses terms such as“produce” and “provide” to describe the disclosed method. These termsare high-level abstractions of the actual operations that can beperformed. The actual operations that correspond to these terms can varydepending on the particular implementation and are, based on thisdisclosure, readily discernible by one of ordinary skill in the art.

In certain embodiments, the delivery systems and methods disclosedherein can be used to deploy a frame member or stent without anexpansion balloon. Thus, many of the difficulties associated with theuse of such expansion balloons for delivering intraluminal devices,particularly intravascular devices, can be avoided or substantiallyeliminated. The delivery systems and methods disclosed herein can besubstantially the same as those used in traditional methods, except thatthe expansion of the prosthetic devices can be achieved by effectingrelative movement between mechanical elements, rather than by theexpansion and contraction of a balloon member.

FIGS. 1-3 disclose an illustrated embodiment of an expandable member(expandable basket) 100 with an open-frame configuration. Expandablemember 100 can comprise a plurality of longitudinally-extending,circumferentially-spaced struts 102 terminating and joined together atopposite ends of the expandable member. As shown in FIG. 1, for example,struts 102 can extend between the distal end 104 and proximal end 106 ofthe expandable member 100. Struts 102 can be formed of a variety ofmaterials and in a variety of shapes, as long as the shape and structureis sufficiently strong to cause expansion of a prosthetic device, asdescribed in more detail below. For example, each strut 102 can beformed of a tubular structure of elastic material, such as stiff plasticor metal. In addition, the expandable member 100 can be formed of avariety of number of struts 102, so long as the struts are of sufficientnumber, strength, and/or shape so as to provide sufficient force tosurfaces and/or contact points of the prosthetic device to expand thedevice as described herein.

The plurality of struts 102 can define an annular supporting surface foran expandable intraluminal device to be delivered. Each strut 102 in theannular array can be laterally deformable to radially expand or radiallycontract the annular array of struts 102, and the annular supportingsurface defined by them.

The expandable member 100 can be expandable between a first ornon-expanded configuration (FIG. 5) to a second or expandedconfiguration (FIG. 1). The expandable member 100 is desirablyconfigured so that shape defined by the annular supporting surface ofthe expandable member in its expanded configuration (FIG. 1) issubstantially predetermined and known. Thus, when the expandable member100 is expanded, the annular supporting surface of the expandable member100 will push against the prosthetic device mounted thereon to expandthe prosthetic device to a predetermined shape (i.e., a shape that iscomplementary to the shape of the expandable member 100 in its expandedconfiguration).

The expandable member 100 can be configured so that it will expand to apredetermined expanded configuration in a variety of ways. For example,struts 102 can be pre-formed or “heat-set” into a desired expandedconfiguration prior to deployment. The pre-formed struts 102 ofperfusion basket 100 may then be stretched down or collapsed into adeployable configuration. By pre-forming struts 102 in this manner, uponexpansion of the expandable member 100, the struts 102 will conform tothe predetermined shape into which they have been pre-formed.

Alternatively, or in addition to pre-forming struts 102, struts 102 mayeach include at least one notch 108 formed at an internal face of adesired bending point 110 on struts 102. Notching the appropriatebending points 110 as shown in FIG. 4, facilitates the bending of struts102 and can provide greater control over the shape of the expandablemember 100 during deployment. Also, notches 108 can allow the struts 102to be deployed using less actuating (e.g., compressive) force. The sizeand depth of notches 108 can vary depending on the strength toformability ratio desired for each strut 102.

A variety of different mechanisms can be used to expand and/or collapseexpandable member 100. In one embodiment, as shown in FIGS. 5-7, themechanism for expanding and/or collapsing the expandable member 100 cancomprise a screw mechanism 120 configured to apply a longitudinal forceto expand or collapse expandable member 100. For clarity, FIGS. 5-7illustrate expandable member 100 with all but one strut 102 removed.Referring to FIG. 5, a prosthetic device (not shown) can be mounted onthe expandable member 100 while it is in a collapsed configuration. Thenthe expandable member 100 can be expanded from the collapsedconfiguration to the expanded configuration shown in FIG. 7. FIG. 6illustrates a partially collapsed configuration, which the expandablemember 100 can pass through during expansion of the expandable member100. Alternatively, the partially collapsed configuration (FIG. 6) canbe the initial configuration of the expandable member 100. In otherwords, the expandable member 100 can be expandable from any firstconfiguration (e.g., the completely collapsed configuration of FIG. 5,the partially collapsed configuration of FIG. 6, or another partiallycollapsed configuration) to a second, expanded configuration (e.g., FIG.7).

When in the lowest profile configuration (i.e., the initial collapsed orpartially collapsed configuration), the proximal end 106 of theexpandable member 100 and the distal end 104 of the expandable memberare furthest apart and screw mechanism 120 is in an extended position.To expand the expandable member 100 and deploy the prosthetic devicemounted thereon, the expandable member 100 can be expanded by actuatingan external mechanism. Actuation of the external mechanism (for example,rotation of actuating member 130 on an external handle as shown in FIG.8) causes screw mechanism 120 to rotate about the longitudinal axis ofthe expandable member 100, as shown by arrow 122 in FIG. 7. As shown inFIG. 8, screw mechanism 120 can have an externally threaded portion 136that is received in an internally threaded portion 134 of distal end104. The rotation of screw mechanism 120 causes the externally threadedportion 136 of screw mechanism 120 to extend further into the internallythreaded portion 134 of distal end 104, causing distal end 104 to movetoward proximal end 106. As the distance between the two ends of theexpandable member 100 shortens, struts 102 are axially compressed (asshown by arrows 121, 124) and forced to radially expand (FIG. 7).

After the prosthetic device is expanded, the expandable member 100 canbe collapsed back to a lower profile configuration for removal from thetreatment site through the patient's vasculature. To return expandablemember 100 to the collapsed configuration (FIG. 5) or partiallycollapsed configuration (FIG. 6), the rotation of screw mechanism 120can be reversed, causing the distance between the proximal end 106 anddistal end 104 of the expandable member 100 to increase and the strutsto radially contract.

FIG. 8 illustrates an embodiment of a delivery system that comprises anexpandable member 100 at a distal end. A rotatable actuating member 130can be coupled to the screw mechanism 120. Screw mechanism 120 canextend longitudinally through one or more shafts 132 and attach to adistal end of expandable member 100. As discussed above, distal end 104of expandable member 100 is preferably coupled to an internally threadedmember 134 that is in threaded engagement with an externally threadedportion 136 of screw mechanism 120. Rotation of actuating member 130causes screw mechanism 120 to rotate, shortening the distance betweenthe proximal end 106 and distal end 104 of expandable member 100 asdiscussed above.

FIG. 9 illustrates an exemplary embodiment of a delivery system 150 fordeploying a prosthetic device 152 using expandable member 100.Prosthetic device 152 can be any expandable intraluminal device, such asan expandable prosthetic heart valve. In this exemplary embodiment,delivery system 150 can include an outer member (shaft) 154 and an innermember (shaft) 156, with outer member 154 coaxially disposed aroundinner member 156. Outer member 154 and inner member 156 can be made fromany number of suitable materials, such as a polymeric or metallicmaterial.

Inner member 156 can comprise an expandable member 100 attached near thedistal end of inner member 156. Inner member 156 can also have a guidewire lumen so that the delivery system 150 can be advanced over a guidewire 158, with the guide wire passing through the lumen. Guide wire 158can be introduced into a body lumen and guided to the proper location inaccordance with the conventional methods that used with balloon-typecatheters. The expandable member 100 and prosthetic device 152 can trackthe guide wire 158 to the target location for deployment of theprosthetic device 152.

FIG. 9 shows struts 102 of the expandable member 100 in a substantiallyunexpanded configuration. FIG. 9 illustrates the expandable member 100in a partially collapsed configuration (as shown in FIG. 6); however, asdiscussed above, expandable member 100 could be further collapsed (asshown in FIG. 5) to achieve a lower profile configuration. Prostheticdevice 152 is shown mounted on the outer surfaces of struts 102, whichcollectively define an annular surface for receiving prosthetic device152 in a contracted state. As shown in FIG. 9, expandable member 100 canbe collapsed into and constrained by the distal end of outer member 154,which forms a sheath extending over the valve. Thus, prosthetic device152 can be constrained and/or positioned in a contracted conditionbetween outer member 154 and the annular surface defined by struts 102.Prosthetic device 152 can be maneuvered through the patient'svasculature to the treatment site while mounted on expandable member100, as shown in FIG. 9.

Alternatively, as described in U.S. Patent Publication No. 2008/0065011and U.S. patent application Ser. No. 12/247,846, the prosthetic device152 can be initially mounted in a collapsed (crimped) state at alocation that is either distal or proximal to expandable member 100. Theentire disclosures of U.S. Patent Publication No. 2008/0065011 and U.S.patent application Ser. No. 12/247,846 are incorporated by referenceherein. After the prosthetic device is advanced through narrow portionsof the patient's vasculature (for example, the iliac artery which istypically the narrowest portion of the relevant vasculature), theprosthetic device can be positioned on (or over) the expandable member100. If the prosthetic device has not yet been advanced to thedeployment site when the expandable member is repositioned underneaththe prosthetic device, then the prosthetic device and expandable membercan be advanced to the treatment site together and the expandable membercan be expanded to deploy the prosthetic device at the treatment site.In this manner, prosthetic device can be crimped to an even smallerdiameter and the profile of the delivery system can be further reduced.

Once the prosthetic device 152 and expandable member 100 reach thedesired deployment location, outer member 154 can be retractedproximally, exposing the prosthetic device 152 for deployment. FIG. 10illustrates the expandable member 100 in an expanded configuration afterthe outer member 154 has been retracted relative to the expandablemember 100. The expansion of expandable member can be caused (asdiscussed above) by actuating screw mechanism 120 to compress theexpandable member 100 longitudinally and force struts 102 to expandradially. As shown in FIG. 10, the delivery system can have an actuatingmember 130 positioned on or around an external handle member 128.External handle member 128 can have visual indicia 131 which indicatethe amount of expansion of expandable member. The rotation of theactuating member 130 (as discussed above, for example, with regard toFIG. 8) forces struts 102 on expandable member 100 to longitudinallycontract and radially expand, causing prosthetic device 152 to beexpanded and anchored at the target location.

The delivery system 150 shown in FIGS. 9 and 10 desirably also comprisesa cover 160 that at least partially surrounds expandable member 100. Asshown in FIGS. 11 and 12, cover 160 can be disposed over a workinglength (prosthetic device mounting area) 162 of the expandable member100, with cover 160 extending the length of prosthetic device 152 andover a proximal end portion 164 of expandable member 100. For clarity,FIG. 11 shows cover 160 partially cut-away, showing the location ofstruts 102 beneath cover 160 at the working length 162 and proximal endportion 164. Desirably, distal end portion 166 remains uncovered asshown in FIG. 11. Cover 160 is desirably attached to the outer surfaceof struts 102 along the working length 162. Cover 160 is desirablyincludes one or more slits 170 and is at least partially detached fromthe outer surface of struts 102 at proximal end portion 164.

Slits 170 can be arranged approximately 120 degrees about thecircumference of cover 160 at proximal end portion 164. Slits 170 allowproximal end portion 164 of cover 160 to act as temporary leaflets 168,which may open (second configuration) when fluid flows throughexpandable member 100 from the distal end 104 to the proximal end 106 asindicated by arrows 172 (FIGS. 10 and 12) and close (firstconfiguration) as when fluid tries to pass through expandable member 100from the proximal end 106 to the distal end 104 as indicated by arrows174 (FIG. 11).

By providing a cover 160 that permits fluid flow in one direction, butrestricts it in the other, the delivery system can mimic a native valvewhile the prosthetic device 152 is being deployed. In conventionalsystems, for example, a balloon member can occlude the orifice (such asthe aortic valve) causing difficulties. The pressure drop across theaortic valve when the valve is closed and the flow across the valve (˜5L/min) is so great that occlusion of the annulus may result in theventricle ejecting the occluding member (e.g., expandable balloon) intothe aorta. By permitting flow through the expandable member, pressurebuild-up during prosthetic device deployment can be avoided.

Also, by allowing fluid to flow through the orifice during deployment ofthe prosthetic device, the need for pacing the heart can be reduced orentirely eliminated. Although current pacing procedures are effective,they still require rapid deployment of prosthetic devices. For example,in certain procedures, the prosthetic device should be deployed in about3 to 5 seconds. Since the deployment systems described herein permitflow across the orifice during deployment of the prosthetic device, theprosthetic device can be deployed more slowly, and can be repositionedand/or moved by an operator during deployment. In contrast, pacingprocedure do not generally allow for any repositioning or movement ofthe prosthetic device during deployment. Additionally, by eliminatingpacing, the procedure can be greatly simplified and variations inpatient anatomy and systems (e.g., ventricular pressure and flow) forthe purpose of pacing need not be considered.

FIG. 13 illustrates a specific embodiment where the prosthetic device152 is a prosthetic heart valve that is to replace the native aorticvalve. The embodiments disclosed herein permit blood to flow from theleft ventricle 182 through the expandable member 100 and into the aorta184. As the prosthetic device 152 is moved into position at the aorticannulus 180, blood can flow from the left ventricle 182 through theaortic annulus 180 into the aorta 184 (as shown by arrow 185). However,when the flow of blood is reversed, cover 160 closes (as shown in FIG.11) and at least substantially blocks blood from flowing from the aorta184 back into the left ventricle 182. Thus, while prosthetic device 152is being deployed cover 160 (and its leaflets 168) open (as shown inFIGS. 10, 13, and 13) allowing blood to flow into the aorta. When theventricles finish contracting and begin to relax, however, cover 160(and its leaflets 168) move against struts 102 at the proximal endportion 164 (FIG. 11) and substantially prevent blood from flowing backinto the left ventricle.

Cover 160 can also provide protection to flexible membranes or othercomponents of the expandable prosthetic device to be delivered byforming a barrier between struts 102 and the prosthetic device duringdelivery and deployment of the prosthetic device at the treatment site.Cover 160 can be formed of any suitable material, including, for exampleurethane and the like. Moreover, instead of the slits 170 and leaflets168 shown in the illustrated embodiments, cover 160 can comprise anysuitable shape and configuration, so long as that shape andconfiguration is suitable to restrict flow in one direction and permitflow in the other direction during placement and deployment of theprosthetic device.

Various prosthetic devices are suitable for deployment with the deliverysystems disclosed herein, including, for example, heart valves thatcomprise expandable frame members and one or more leaflet membersattached to the expandable frame members. After deployment of theprosthetic device, the expandable member can be radially contracted asdiscussed above and the expandable member can be retracted from thebody.

In other embodiments, the prosthetic device itself can comprise at leasta portion of the expandable member. FIG. 14 is an illustration of adelivery system 200 where the open-frame expandable member comprises aprosthetic device. In the illustrated embodiment, delivery system 200comprises an implantable prosthetic device 202 (hereinafter “valve 202”)that is suitable for percutaneous deployment and that is releaseablycoupled to expansion struts 216 to form an expandable member. Valve 202is preferably adapted to be radially crimped and radially expanded,which simplifies navigation through the narrow passages of the patient'svasculature during delivery and positioning of valve 202. Valve 202preferably also comprises a flexible membrane 204 and a collapsiblesupport structure (frame) 206.

After deployment at a treatment location, flexible membrane 204 can bepositioned in a flow path through valve 202 to permit flow in a firstdirection, and substantially resist flow in a second direction. In oneembodiment, flexible membrane 204 can include a collapsible pliantmaterial formed as flexible leaflets 208, which can be arranged tocollapse in, for example, a mono cusp, bicuspid, or tricuspidarrangement.

In the illustrated embodiment, collapsible support structure 206 can beexpandable from a first diameter to a second diameter, and can have aflow path through the collapsible support structure 206 along itsstructural axis. Collapsible support structure 206 can include agenerally cylindrical expandable framework of frame members 210, whichprimarily secure valve 202 at or adjacent to the defective valveannulus. Collapsible support structure 206 can provide stability to thevalve 202 and help to prevent valve 202 from migrating after it has beenimplanted.

Prosthetic valves of this type are usually implanted in one of thechannels of the body to replace a native valve. In the illustratedembodiment, the prosthetic valve will be explained in connection with acardiac valve prosthesis configured for implantation at the aorticannulus; however, it should be understood that the delivery systemsdisclosed herein can be used with other expandable members andprosthetic devices.

Collapsible support structure 206 may be a support stent configured tocrimp evenly so as to present a relatively low profile or narrowconfiguration. The collapsible support structure 206 can also beradially deployable from the low profile configuration so as to extendto occupy the passage at the target location for implantation in a bodyduct. In one embodiment, collapsible support structure 206 can comprisea series of frame members (struts) 210 arranged and connected to definea geometrical structure that causes collapsible support structure 206 toexpand radially as the structure is compressed axially. For example,frame members 210 can define substantially diamond shaped cells 212 thatwhen axially compressed force collapsible support structure 206 toexpand radially. Valve 202 can be releasably coupled to connectingstruts (linkages) 216 at attachment areas 214 located at proximal anddistal ends of valve 202.

In operation, a delivery catheter advances valve 202 while coupled toexpansion struts 216 through a sheath over a guidewire to a targetlocation in a body duct, for example, the aortic valve. As shown in FIG.14, when in a collapsed position, connecting struts 216 can be disposedsubstantially axially relative to the deployment system. To expand valve202, the distance between distal end 104 and proximal end 106 can beshortened by rotating screw mechanism 120. As discussed above, therotation of screw mechanism causes distal end 104 to move closer toproximal end 106, which forces connecting struts 216 to extend radially.To facilitate the radial expansion of connecting struts 216, theconnecting struts can have hinge or bend areas 217, about which theconnecting struts bend. These bend areas can be pre-formed or notched,or otherwise configured so that connecting struts 216 will radiallyextend at the bend area 217 when they are axially compressed.

Because connecting struts 216 are connected to frame members 210 atattachment areas 214, the radial expansion of connecting struts 216applies radially directed forces to the valve 202 via frame members 210.The radially movement of connecting struts 216 causes valve 202 toradially expand (deploy). As shown in FIG. 16, once valve 202 begins toexpand, leaflets 204 may be immediately activated and begin to regulateflow through the annulus. Once valve 202 is completely deployed,connecting struts 216 may be disengaged from attachment areas 214 andremoved from the target location.

In a specific implementation shown in FIGS. 17A, 17B, and 18, connectingstruts 216 can be pivotably coupled to a portion of annular members 230,232 at pivot connection areas (bending areas) 234. For example, in oneembodiment, the proximally located connecting struts can be coupled to afirst annular member 230 at the proximal end and distally locatedconnecting struts can be coupled to a second annular member 232 at thedistal end. Annular members 230 and 232 can comprise a plurality ofadjacent, circumferentially spaced extending members 236 with spaceslocated between adjacent extending members 236 for receiving connectingstruts 216. Connecting struts 216 can be positioned and captured betweenextending members 236 and configured to pivot or bend about pivotconnection area 234. A ring member 219 can pass through each of theconnecting struts 216 to hold each connecting strut 216 in position atone of the annular members 230 and 232.

In this and in the other embodiments, the number of connecting struts216 can vary. For example, FIG. 17B illustrates four circumferentiallyspaced connecting struts 216; however, more or fewer connecting struts216 can be used, so long as the outwardly directed force generated bythe connecting struts 216 as they undergo compression is sufficient toexpand valve 202 from an unexpanded configuration with a smallerdiameter to an expanded configuration with a greater diameter. In theillustrated embodiment, FIG. 17B shows eight different locations betweenextending members 236 into which connecting struts 216 can be located.

Relative movement of annular members 230 and 232 can be caused by ascrew mechanism or other axially applied forces (as described in moredetail above), causing connecting struts 216 to expand radially. Toexpand valve 202 uniformly, it can be desirable to space connectingstruts 216 annularly around annular members 230 and 232. In addition, itmay be desirable to connect struts 216 to the valve at areas where thevalve has structural supports or posts so that the valve has sufficientrigidity at the area where struts 216 contact valve 202.

Various means for attaching connecting struts 216 to valve 202 can beused. For example, connecting struts 216 can have a first end pivotablycoupled to annular members 230 and 232, and a second end that comprisesa securing mechanism for securing the valve 202 to the connecting strutas shown in FIG. 18. For example a wire member 238 can pass throughconnecting strut 216 and a portion of the valve 202 can be capturedbetween wire 238 and a holding area 240 of connecting strut 216 (e.g.,wire member 238 can pass through a loop or opening formed in one ofstruts 210 and positioned in area 240). The valve 202 can be releasedfrom connecting strut 216 by pulling wire 238 towards a proximal end (inthe direction of arrow 242) a distance great enough to release valve 202from the holding area 240.

FIGS. 19-21 show an embodiment of an expandable anchoring device 300that can be used to hold a valve 302 in a desired position duringdeployment of valve 302. As shown in FIG. 19, anchoring device 300 caninclude a plurality of flexible members, or fingers, 304. These flexiblemembers 304 can be used to anchor the delivery system in place duringdeployment of valve 302. As shown in FIG. 20, for example, duringdeployment of a prosthetic device (valve 302) at an aortic annulus,flexible members 304 can be expanded in the left ventricle, whereflexible members 304 can be configured to contact a portion of tissuesurrounding the native aortic valve 310. Once deployed, anchoring device300 can fix the position of valve 302 relative to the native valve 310.Thus, valve 302 can then be expanded in the native valve 310 withoutconcern for positioning error caused by, for example, movement of thebeating heart or the blood pressure through the native valve 310.

In addition, anchoring device 300 can help hold the valve in the properposition by preventing the delivery system from moving proximally duringdeployment. For example, after expansion of anchoring device 300 withinthe left ventricle, the delivery system can be moved proximally untilthe anchoring device 300 contacts the ventricle walls near the aorticannulus, effectively preventing the delivery system from moving anyfurther proximally. After the anchoring device 300 secures the relativeposition of the prosthetic device (valve), the prosthetic device can beexpanded at the aortic annulus.

Referring to FIGS. 21A and 21B, the anchoring device 300 can bedelivered to the treatment site (or anchoring location) constrained inan outer member (cover) 314. To deploy anchoring device 300, outermember 314 can be retracted, exposing flexible members 304. Flexiblemembers 304 can be biased outwards and upon retraction of the covermember 314, flexible members 304 radially expand and can be placed incontact with tissue near the native annulus 310. The expandable portionof the anchoring device can be formed in a variety of shapes. Forexample, if desired, flexible members 304 can be replaced with anexpandable braided cup. After positioned appropriately, valve 302 can beexpanded using a member 315, which can be, for example, an expandablemember as described herein or a balloon member.

To remove anchoring device 300 from the treatment location, a retractioncollar 308 can be utilized to “recapture” flexible members 304. In oneembodiment, a pull wire 312 can be attached to a collar 308 that islocated near the distal ends of flexible members 304 of anchoring device300. By pulling pull wire 312 proximally, the collar 308 can moveproximally over flexible members 304, causing them to radially collapsealong the axis of the delivery system. Once collapsed, the anchoringdevice 300 can be removed from the treatment site by being retractedfrom the body through a catheter of the delivery system.

Screw mechanism 120 is a particularly desirable mechanism for expandingthe expandable member, since it can provide significant compressiveforce at a local area (e.g., the expandable member), thereby forcing theexpandable member to radially expand without imparting significantforces throughout other locations of the delivery system. However, asdiscussed above, other mechanisms for expanding the expandable membercan be utilized. For example, FIG. 22 illustrates another embodiment ofa deployment system where the distance between the distal end 104 andproximal end 106 of an expandable member 100 can be adjusted to expand avalve or other prosthetic device.

In this embodiment, the distance between the two ends of the expandablemember can be adjusted by applying a longitudinal (non-rotational) forcethe length of the deployment system 400. As with the other deploymentsystems described herein, deployment system 400 can be used fordelivering a prosthetic device, such as a heart valve, but is notlimited thereto, and may be adapted to stent delivery systems as well.In one embodiment, deployment system 400 can include a shaft 402 thatcan track through the vasculature and yet have sufficient “longitudinal”compressive strength to allow a wire or cable 404 to be pulled through acenter lumen defined through shaft 402 with sufficient force to deploy,for example, expandable member 100 (shown with some struts 102 removedfor clarity).

In one embodiment, one end of wire 404 extends through expandable member100 and is coupled to distal end 104 of expandable member 100. Aproximal end of wire 404 is operatively coupled to a handle 406 tointerface with a ratcheting mechanism 420 (shown in FIG. 24).

Ratcheting mechanism 420 may be activated, for example, by gripping andsqueezing handles 408 and 410 (FIG. 22) to cause wire 404 to be pulledproximally through the center lumen of shaft 402 and locked into placeby opposing locking wheels 422, 424 (FIG. 24) in a manner well known bythose of ordinary skill in the art. Other locking elements 439 can beprovided to at least temporary secure the position of wire 404 relativeto shaft 402. A release knob 412 may also be included on handle 406 andused to release locking wheels 422, 424 and the tension on wire 404 asdesired.

FIG. 23 is a cross sectional view along the longitudinal length offlexible shaft 402. In one embodiment, flexible shaft 402 is composed ofa circular cross section closed wound coil 430 interposed with atriangular cross section closed wound coil 432. Each coil 430 and 432 isconfined within a tubular cover 434, which can be made of vinyl or asimilar material. Coils 430 and 432 define a lumen extending the lengthof flexible shaft 402 with wire 404 disposed therein.

In operation, once expandable member 100 is positioned as desired in thevasculature, ratcheting mechanism 420 of handle 406 can be activated.Ratcheting mechanism 420 pulls proximally (in the direction of arrow438) on wire 404, this in turn, pulls distal end 104 of expandablemember 100 toward proximal end 106 to cause expandable member 100 to“deploy” in a manner previously described. The resulting force (shown byarrow 440) used to pull on wire 404 is transferred to shaft 402, whichis configured to absorb the compressive load and resist compression(shown by arrow 442) without significant buckling or shape distortion ofshaft 402.

Since shaft 402 provides a stable mounting platform, in an alternativeembodiment, instead of deploying expandable member 100 by pulling onwire 404, a rotation actuator 450 can be used. Advantageously, sincerotation actuator 450 is mounted to a “rigid” platform, the twistingactuation is acceptable.

The mechanisms described herein can also be actuated by a variety ofpower sources. For example, the screw mechanisms described above can beactuated using a power source such as a motor or battery. In theillustrated embodiment shown in FIG. 25, a rotation actuator 450, suchas DC motor or equivalent, is coupled to the distal end 452 of shaft402. In this embodiment, rotation actuator 450 may be coupled to a driveshaft 454, such as a threaded rod. Drive shaft 454 can be operativelyengaged with a threaded receptacle 456 positioned on a distal end 104 ofexpandable member 100 (some struts 102 removed). Operationally, rotationactuator 450 makes drive shaft 454 rotate causing threaded receptacle456 to traverse linearly upon drive shaft 454. The linear movement ofthreaded receptacle 456 toward proximal end 106 causes distal end 104 tomove toward proximal end 106 to deploy expandable member 100.

In one embodiment, a gear reduction mechanism 460 can be added torotation actuator 450 to create a higher output torque and also allowfor fine tuning of the placement procedure. It should be understood thatvariations in motor voltage (DC only), gearbox ratios, and screw threadpitch may be used to obtain the required or desired torque needed todeploy expandable member 100.

The apparatuses and methods described herein can improve what currentlyis one of the most critical stages of the deployment procedure byallowing a physician to more accurately position and deploy a prostheticdevice without disrupting patient hemodynamics.

Although the specific embodiments discussed above describe methods andapparatuses for expanding various prosthetic devices, it should beunderstood that the devices and methods disclosed herein can be used forother purposes. For example, the expandable members disclosed herein canbe used to replace expandable balloon members in a variety of medicalprocedures. Thus, the expandable members described herein can be used,for example, for angioplasty (e.g., opening clogged coronary arteries),valvuloplasty (e.g., dilating a stenotic heart valve), and otherprocedures in which expanding balloon members are conventionallyutilized.

The invention has been disclosed in an illustrative manner. Accordingly,the terminology employed throughout should be read in an exemplaryrather than a limiting manner. Although minor modifications of theinvention will occur to those of ordinary skill in the art, it shall beunderstood that what is intended to be circumscribed within the scope ofthe patent warranted hereon are all such embodiments that reasonablyfall within the scope of the advancement to the art hereby contributed,and that scope shall not be restricted, except in light of the appendedclaims and their equivalents.

We claim:
 1. A method for delivering an expandable prosthetic heartvalve through a patient's vasculature, the method comprising: insertinginto the patient's vasculature a distal end portion of a deliveryapparatus and the expandable prosthetic heart valve mounted in aradially compressed state along the distal end portion, the deliveryapparatus comprising: an elongate shaft having a proximal end configuredto remain external to the patient's body and a distal end configured forinsertion into the patient's vasculature; an actuator that is coupled tothe shaft; a gear mechanism that is connected to the distal end of theshaft; and a screw mechanism operatively coupled to the actuator by thegear mechanism; using the elongate shaft, advancing the expandableprosthetic heart valve, the screw mechanism, and the gear mechanismthrough the patient's vasculature; and once the expandable prostheticheart valve, the screw mechanism, and the gear mechanism are positionedwithin the patient's vasculature, actuating the actuator in a firstactuation direction to produce rotation of the screw mechanism via thegear mechanism to radially expand the prosthetic heart valve.
 2. Themethod of claim 1, further comprising actuating the actuator in a secondactuation direction to produces rotation of the screw mechanism via thegear mechanism to radially compress the prosthetic heart valve.
 3. Themethod of claim 1, wherein the actuator comprises a DC motor.
 4. Themethod of claim 1, further comprising releasing the expandableprosthetic heart valve from the delivery apparatus.
 5. The method ofclaim 4, wherein releasing the expandable prosthetic heart valve fromthe delivery apparatus comprises pulling in a proximal direction a wiremember connected to the expandable prosthetic heart valve to release theprosthetic heart valve from the delivery apparatus.
 6. The method ofclaim 1, wherein the gear mechanism comprises a gear reduction mechanismcoupled to the actuator.
 7. The method of claim 6, wherein the gearreduction mechanism receives an input torque from the actuator androtates the screw mechanism at an output torque different than the inputtorque to expand the expandable prosthetic heart valve.
 8. The method ofclaim 6, wherein the gear reduction mechanism receives an input speedfrom the actuator and rotates the screw mechanism at an output speeddifferent than the input speed to expand the expandable prosthetic heartvalve.
 9. A method for delivering an expandable prosthetic heart valvethrough a patient's vasculature, the method comprising: inserting intothe patient's vasculature a distal end portion of a delivery apparatusand the expandable prosthetic heart valve mounted in a radiallycompressed state along the distal end portion, the delivery apparatuscomprising: an elongate shaft having a proximal end configured to remainexternal to the patient's body and a distal end configured for insertioninto the patient's vasculature; an actuator that is coupled to theshaft; a gear mechanism that is connected to the distal end of theshaft; and a screw mechanism operatively coupled to the actuator by thegear mechanism; using the elongate shaft, advancing the expandableprosthetic heart valve, the screw mechanism, and the gear mechanismthrough the patient's vasculature; and once the expandable prostheticheart valve, the screw mechanism, and the gear mechanism are positionedwithin the patient's vasculature, actuating the actuator, whereinactuating the actuator produces rotation of the screw mechanism via thegear mechanism, wherein the gear mechanism receives an input torque fromthe actuator and rotates the screw mechanism at an output torquedifferent than the input torque to expand the expandable prostheticheart valve.
 10. The method of claim 9, wherein the actuator ispositioned at the distal end of the shaft.
 11. The method of claim 9,wherein the actuator further comprises one or more external controls,the method further comprising actuating the one or more externalcontrols to cause actuation of the actuator in the first actuationdirection within the patient's body to expand the expandable prostheticdevice.
 12. The method of claim 11, wherein the one or more controlscomprise a knob, and wherein actuating the one or more controlscomprises turning the knob in a first direction to expand the expandableprosthetic device.
 13. The method of claim 12, further comprisingturning the knob in a second direction to compress the expandableprosthetic device.
 14. The method of claim 9, wherein the deliveryapparatus comprises an external handle comprising visual indiciaindicating an amount of expansion of the expandable prosthetic heartvalve.
 15. A method for delivering an expandable prosthetic devicewithin a patient's vasculature, the method comprising: inserting theexpandable prosthetic device into the patient's body utilizing adelivery system comprising: an elongate shaft having a proximal endconfigured to remain external to the patient's body and a distal endconfigured for insertion into the patient's vasculature; an actuatorthat is coupled to the shaft; a gear mechanism that is connected to thedistal end of the shaft; the expandable prosthetic device disposed onthe distal end of the shaft; and a screw mechanism connected to theexpandable prosthetic device, wherein the screw mechanism is operativelycoupled to the actuator by the gear mechanism; using the elongate shaft,advancing the expandable prosthetic device, the screw mechanism, and thegear mechanism to a position within the patient's vasculature; and oncethe expandable prosthetic device, the screw mechanism, and the gearmechanism are positioned within the patient's vasculature, actuating theactuator, wherein actuating the actuator produces rotation of the screwmechanism via the gear mechanism, the gear mechanism wherein the gearmechanism receives an input speed from the actuator and rotates thescrew mechanism in a first screw rotation direction at an output speeddifferent than the input speed to expand or compress the expandableprosthetic device.
 16. The method of claim 15, wherein the screwmechanism comprises a threaded rod.
 17. The method of claim 15, whereinrotation of the screw mechanism in the first screw rotation directionapplies a proximally directed force to a first location and a distallydirected force to a second location.
 18. The method of claim 17, furthercomprising: actuating the actuator in a second actuation directionopposite the first actuation direction, wherein the actuation of theactuator in the second actuation direction causes rotation of the screwmechanism in a second screw rotation direction, wherein rotation of thescrew mechanism in the second screw rotation direction applies adistally directed force to the first location and a proximally directedforce to the second location.
 19. The method of claim 15, whereinrotation of the screw mechanism in the first screw rotation directionapplies a first longitudinal force to a proximal end portion of theexpandable prosthetic device and a second longitudinal force to a distalend portion of the expandable prosthetic device, wherein the firstlongitudinal force and the second longitudinal force extend inrespective directions toward each other, thereby causing the expandableprosthetic device to radially expand.
 20. The method of claim 19,further comprising: actuating the actuator in a second actuationdirection opposite the first actuation direction, wherein the actuationof the actuator in the second actuation direction causes rotation of thescrew mechanism in a second screw rotation direction, and in response torotating the screw mechanism in the second screw rotation direction, thefirst longitudinal force and the second longitudinal force extend inrespective directions away from each other, thereby causing theexpandable prosthetic device to radially compress.